Conventional incandescent lamps, fluorescent lamps, and neon tubes have long been used to illuminate many large-scale commercial and public signs. The market is now, however, demanding larger displays with the flexibility to customize display sizes and colors which are not possible with these older technologies. As a result, many displays now utilize LEDs in their design because LEDs consume less electrical energy than conventional light sources and possess a much longer lifetime with lower maintenance costs.
LED technology is currently being applied to large-scale display applications, such as outdoor or indoor stadium displays, large marketing advertisement displays, and mass-public informational displays. Many of these large-scale applications are dynamically reconfigurable under computer control. In addition, some large-scale animated displays that are capable of displaying video imaging are now being produced. Other simpler types of illuminated signs also use LEDs, including outdoor signs in which LED arrays are used to illuminate a sign plate from its sides. Additionally, LEDs are used in many temporary sign applications, such as large banners at trade shows, that require bright, eye-catching, flexible systems that are easily portable.
Currently, large-scale display systems are supported by structural members such as metal frames and other types of rigid brackets in which orthogonal LED modules are bolted in place to the structural members. However, standard metal brackets are restrictive, often yielding only orthogonal two-dimensional (2D) displays, and therefore do not lend themselves to the variety of applications in which the front face of the overall display is a simple or complex three-dimensional (3D) curved surface. There is a demand in the market not only for 2D displays, but also for 3D displays. Technical challenges exist in forming a display system with the flexibility to form various 2D or 3D shapes and, furthermore, in providing control of such a system. What is needed is a system of individual pixel elements that are configurable to form LED displays having 2D or 3D shapes.
In addition, brackets and other similar support systems often employ cumbersome methods of fixing LED modules to the frame, such as mechanical fasteners. Such methods do not allow for the easy removal and replacement of individual LED modules, thereby making maintenance difficult. For example, in a current system, if a LED module becomes inoperative, replacement typically requires access to the rear of the display and involves removing screws, bolts, connectors and other mechanical fasteners, resulting in a process that is tedious and time consuming.
What is further needed is a system with a LED module design that allows easy installation and easy replacement of modules from the front or the rear of a large-scale display.
An example of a LED pixel module that is used to display a pixel on a large-scale display is described in U.S. Pat. No. 5,410,328, entitled, “Replaceable intelligent pixel module for large-scale LED displays.” This patent describes an apparatus for a detachable LED pixel module that contains a plurality of LEDs along with a processor with input and output capabilities. The rear wall includes an aperture to receive an electrical jack from the display so as to communicate data, power and commands to the LED module. The input and output capabilities of the processors along separate data paths allow modules to be “daisy-chained” together, allowing data to be passed through a succession of modules that receive power and monitor command signals from the interconnecting ribbon cables.
Although the apparatus of U.S. Pat. No. 5,410,328 is capable of displaying a pixel on a large-scale display, this patent makes no claim concerning its applicability in non-planar large-scale displays.